Release v0.1.0

vendor/github.com/muun/libwallet/hdpublickey.go

@@ -0,0 +1,96 @@
+package libwallet
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/pkg/errors"
+
+	"github.com/btcsuite/btcutil/hdkeychain"
+)
+
+// HDPublicKey is an HD capable pub key
+type HDPublicKey struct {
+	key     hdkeychain.ExtendedKey
+	Network *Network
+	Path    string
+}
+
+// NewHDPublicKeyFromString creates an HD pub key from a base58-encoded string
+// If the parsed key is private, it returns an error
+func NewHDPublicKeyFromString(str, path string) (*HDPublicKey, error) {
+
+	key, network, err := keyFromString(str)
+	if err != nil {
+		return nil, err
+	}
+
+	if key.IsPrivate() {
+		return nil, errors.New("encoded key was not a public key")
+	}
+
+	return &HDPublicKey{key: *key, Network: network, Path: path}, nil
+}
+
+// String return the key base58-encoded
+func (p *HDPublicKey) String() string {
+	return p.key.String()
+}
+
+// DerivedAt derives a new child pub key
+// index should be uint32 but for java compat we use int64
+func (p *HDPublicKey) DerivedAt(index int64) (*HDPublicKey, error) {
+
+	child, err := p.key.Child(uint32(index))
+	if err != nil {
+		return nil, err
+	}
+
+	path := fmt.Sprintf("%v/%v", p.Path, index)
+	return &HDPublicKey{key: *child, Network: p.Network, Path: path}, nil
+}
+
+func (p *HDPublicKey) DeriveTo(path string) (*HDPublicKey, error) {
+
+	if !strings.HasPrefix(path, p.Path) {
+		return nil, errors.Errorf("derivation path %v is not prefix of the keys path %v", path, p.Path)
+	}
+
+	firstPath, err := parseDerivationPath(p.Path)
+	if err != nil {
+		return nil, errors.Wrapf(err, "couldn't parse derivation path %v", p.Path)
+	}
+
+	secondPath, err := parseDerivationPath(path)
+	if err != nil {
+		return nil, errors.Wrapf(err, "couldn't parse derivation path %v", path)
+	}
+
+	indexes := secondPath.indexes[len(firstPath.indexes):]
+	derivedKey := p
+	for depth, index := range indexes {
+		if index.hardened {
+			return nil, errors.Errorf("can't derive a hardened pub key (path %v)", path)
+		}
+
+		derivedKey, err = derivedKey.DerivedAt(int64(index.i))
+		if err != nil {
+			return nil, errors.Wrapf(err, "failed to derive key at path %v on depth %v", path, depth)
+		}
+	}
+	// The generated path has no names in it, so replace it
+	derivedKey.Path = path
+
+	return derivedKey, nil
+}
+
+// Raw returns the backing EC compressed raw key
+func (p *HDPublicKey) Raw() []byte {
+
+	key, err := p.key.ECPubKey()
+	if err != nil {
+		panic("failed to extract pub key")
+	}
+
+	return key.SerializeCompressed()
+}